Good point there
Oh and holy, stop whining, you just don't like the barcarolle
You're completely wrong there, I'm a very very big fan of Chopin and especially of the Barcarolle.
Try it: tonight put on tempest and then Barcarolle on your stereo. Tomorrow the other way round.
As far as encores:
I think "Au bord d'une source" would be great
If you want something off-beat "Boogie Woogie etude" by morton gould
check it out for the effect on the audience:
etincelles moszkowski
Etude OP 72/6 moszkowski
I wouldn't take something that's too well known (One expects to hear the cd one has at home and doesn't go home with your "pianistic identity" ) and also not too long but go for one sparkling encore (like etincelles ) and one musical one eg (eg Siloti Bach)